(1) Field of the Invention
The invention is concerned with latex systems for use in the manufacture of paper and with paper products containing a dried composite of (a) paper-making pulp, (b) a cationic latex and (c) a water-soluble anionic polymer of acrylamide.
(2) Description of the Prior Art
The use of latex in the manufacture of paper by wet-end addition, or as a beater additive, is well known. Commonly, the latex has been an anionic latex but a water-soluble cationic deposition aid has been used therewith. Because of the slightly anionic nature of pulp, it has been suggested that a low-charge density cationic latex should be used in order to get good deposition on the fibers without the use of a deposition aid.
Combinations of anionic and cationic wet-end additives in which both species are water-soluble are known. However, the combination as wet-end additives of a cationic latex with a water-soluble anionic polymer is not known, particularly latexes having particles with a high density of pH independent bound charge at or near the particle surface.